The present invention relates to power generating units such as compressors, electrical generators and welding power supplies, and particularly units of this type that can be transported to a work site.
Portable units that can be carried to a site are known, and a typical unit of this type, such as a TS 200, Model 5000 welder/generator sold by Burco/Mosa, includes an open, lightweight frame consisting of a metal shell on which is mounted an internal combustion engine directly connected to an alternator, which generates sufficient amperage to operate direct current welders and to provide some auxiliary alternating current for operating auxiliary equipment. A engine is also mechanically coupled to a compressor that may be used to provide the compressed air needed to operate a plasma cutting torch used in conjunction with the welding equipment.
While units of this type operate satisfactorily, they have several disadvantages. First, and most importantly, even though the welder/generator or compressor is portable, it is nevertheless difficult and time consuming to load and unload, then connect up the various components which are included in the system. More specifically, in a typical operation, the portable welder/generator, which may weigh approximately 400 pounds, is lifted onto the bed of a pickup truck. Because it is so heavy, it is usually placed at the rear of the bed to avoid unnecessary lifting, and because it is so big, it creates an obstacle that makes it difficult to place any significant equipment in the pickup truck. Next, the compressor, which is a separate unit and also heavy (e.g. 150 pounds), must be lifted and placed on the bed of the pickup truck. At the job site, these units are generally unloaded from the truck, and in any event, they must be connected to one another, and with the welding and plasma cutting equipment, all of which is time consuming and often requires additional lifting of heavy equipment.
Moreover, even though the individual components of the system are relatively heavy, they nevertheless can be stolen and carried away from the back of a pickup truck. Therefore, it is the general practice of those who use such equipment to unload and properly store the equipment in a secure location at the end of each working day, and again, this results is a significant amount of lifting of heavy equipment. The same is true for smaller, auxiliary tools that are used with these units, such as plasma cutters, mig welders and/or welding leads, all of which must also be removed from the truck and stored.
Finally, in such known units, the tubular frame in which the internal combustion engine and the alternator are carried is entirely open, and, as a result, workmen and others located near the equipment are constantly exposed to very high levels of noise resulting from the operation of the engine, the alternator, and the associated compressor unit.
Colella, U.S. Pat. No. 6,051,809, describes a welder/generator and compressor unit that is sized to fit in the bed of a pickup truck. Specifically, the unit has a generally T-shaped cross section, with a lower housing portion sized to fit between the bed walls of a standard pickup truck bed. The upper portion of the housing is somewhat wider, extending over and resting on the bed walls, thus forming the T-shape. On one end of the upper portion of the housing are controls for connection to the welder/generator and compressor. Within the housing are various components including an internal combustion engine, alternator, and air compressor, as well as a compressed air tank for storing compressed air produced by the compressor, a battery, electrical and compressed air connections and a storage area. The engine, alternator and compressor are mounted in longitudinal alignment, with the drive shaft of the engine directly mechanically driving the shaft of the alternator and also mechanically driving the shaft of the air compressor through a speed-reducing pulley arrangement.
The Colella device has the advantage of being easily transportable in the pickup truck bed, and having conveniently located controls and connections to permit use of all of the units without removal from the pickup truck. Furthermore, the enclosed housing provided in the Colella device allows for some reduction of noise.
Unfortunately, the device shown in the Colella patent has a number of drawbacks. First, there is no provision in the described device for storage of fuel for the engine. Presumably, a fuel tank would be provided within an unused portion of the housing or in the truck bed adjacent to the unit. In such a position, the tank would be difficult to access for refueling. Furthermore, in typical use, the Colella device would remain within the pickup truck bed at all times. Therefore, when the fuel tank (wherever positioned) is refilled, spilled fuel would fall into the housing or truck bed soiling the bed or housing and creating a potential safety hazard. Similarly, the Colella patent does not describe a purge valve for the compressed air tank which would be needed to purge condensed water from the tank. Typically, such a valve is located on the tank. However, such a location would be inconvenient. Also, when a purge valve on the compressed air tank is opened to purge water from the tank, water is likely to be emitted into the housing, introducing unwanted moisture into the housing.
A second difficulty with the Colella design is that it is sized to fill the entire width of a pickup truck bed. As a consequence, the unit can only be readily installed adjacent the tailgate of the truck bed, to the rear of the wheel wells, for the reason that the width of the unit prevents sliding the unit past the wheel wells. Although the unit may be lifted over the wheel wells to a forward position in a short bed truck, the unit may be required to be placed in a rearward position for the reason that a short bed truck permits insufficient space (only about one foot) for the Colella unit to fit between the wheel wells and forward end of the truck bed. Positioned in a rearward bed location, the unit limits other uses of the truck bed, as items must be lifted over the bed walls to be placed in the bed, rather than sliding those items into the bed via the tail gate. Furthermore, with the Colella unit in the truck bed, the length of the bed is shortened such that the bed may no longer accommodate typical construction materials such as plywood sheets.
A third difficulty with the Colella design arises when fitting the unit to pickup trucks of different makes and models. While there is, to a reasonable extent, a standard pickup bed width, there is no standard height for pickup bed walls. As a result, the intended fit of the Colella unit, to rest on the pickup walls, will likely be correct for only a certain class of pickups. When the unit is installed in other classes of pickups, it is likely to either rest on the floor of the truck bed with the upper housing sections inconveniently elevated above the top of the bed walls, or, alternatively, rest on the top of the bed walls but with a substantial gap between the bottom of the housing and the bed floor. In the former case, the housing floor would need to be designed to distribute weight to prevent damage to either the unit or truck bed when the unit is resting on its bottom surface. The only way to avoid such issues would be to reduce the height of the lower housing of the unit to a height less than the shortest bed wall in which the unit might be used, which would reduce the volume of the housing available for the identified components.
In addition to the foregoing difficulties, there is the further complication that the total weight of the various elements called for in the Colella patent can easily approach 800 pounds, exceeding the weight that can be supported by typical truck bed rails, and requiring substantial reinforcement of the upper housing portions to support the unit in the intended manner.
A further difficulty with the Colella unit arises from the manner in which elements are positioned within the housing. The longitudinal, mechanically coupled arrangement of the engine, alternator and compressor makes efficient use of the space; however, it hinders the efficient flow of cooling air to those elements since such units are typically designed to obtain or exhaust cooling air in the longitudinal direction, and each element is longitudinally abutting either another element or the housing and truck bed walls. As a consequence, cooling air flow may be restricted and/or heated air may be caused to flow from one unit onto another, limiting cooling.
Finally, the Colella unit, while portable, may have limitations in some environments where a pickup truck cannot be positioned close to the work area, for example, where welding is being performed deep within a structure, it may be inconvenient, or detrimental to weld power, to run long electrical leads carrying welder voltages and currents from an externally-parked pickup truck to the work site.
The present invention provides a compact, efficient and secure integrated power unit for use in a bed of a pickup truck. The integrated power unit of the present invention is fully self contained, user friendly and relatively quiet in operation. The integrated power unit of the present invention conveniently fits at the forward end of a pickup truck bed and even fits between the rear wheel wells of the truck bed. Further, the integrated power unit of the present invention can be adjustably assembled so that it can be easily installed in a wide range of different pickup trucks. The integrated power unit of the present invention is especially useful where a wide range of power requirements are necessary. The integrated power unit of the present invention readily provides regulated and unregulated compressed air and an electrical power supply, thereby providing power for a wide range of electrically and pneumatically powered tools.
According to the principles of the present invention and in accordance with the preferred embodiments, the invention provides an integrated power unit for use with a pickup truck. The power unit has a lower housing located between opposed side walls in the truck and an upper housing that extends from the lower housing and over a sidewall of the truck bed. An electrical power generating unit and a plurality of electrical breakers are also located in the lower housing.
In another embodiment, the lower housing of the integrated power unit has a lid movable with respect to the lower housing and a switch mounted in the lower housing to detect when the lid is opened and closed. The switch is electrically connected with the internal combustion engine and disables the engine in response to the lid being opened.
In a further embodiment of the invention, the integrated power unit has a compressor located in the lower housing connected to the electrical power generating unit. A compressed air tank is also located in the housing and is connected to the compressor. A control panel has a gauge fluidly connected to the compressed air tank for displaying fluid pressure within the compressed air tank. In one aspect of this invention, the control panel is mounted in the upper housing. In another aspect of this invention, the control panel has a switch for enabling and disabling the compressor.
In a still further embodiment of the invention, the integrated power unit has an internal combustion engine and a first air flow path within the lower housing for receiving cooling air from outside the housing and directing the cooling air past the engine to a location outside of the housing. In addition, the integrated power unit has a power converting unit connected to the engine and a second air flow path within the lower housing. The second air flow path receives cooling air from outside the housing and directs the cooling air past the power converting unit to a location outside of the housing. In various aspects of this embodiment, the air flow paths extend through different walls of the integrated power unit.
The above and other objects and advantages of the present invention will become more readily apparent during the following detailed description taken in conjunction with the drawings herein.